Grinding machine



1943- A. E. MANDEVILLE ETAL 2,336,796

GRINDING MACHINE Filed Aug. 28, 1942 s Shets-Sheet 1 A. E. MANDEVILLEETAL GRINDING MACHINE Filed Atig. 28, 1942 3 Sheets-Sheet 2 PatentedDec. 14, 1943 GRINDING MACHINE Adrien E. Mandeville, Pawtucket, andLester J. Lalime, Providence, It. I.,. assignors to Brown and SharpeManufacturing Company, a corporation of Ithode Island Application August28, 1942, Serial No. 456,484

9 Claims. (01. 51-115) The present invention relates to improvements ingrinding machines, and more particularly to an indexing mechanism forpositioning different faces of the work successively for grinding.

It is an object of the invention to provide in a cylindrical typegrinding machine, a novel construction and arrangement of the severalcooperating instrumentalities of the machine suitable for the grindingof relief surfaces upon both faces of a milling cutter as compositeparts of a complete grinding operation which the machine is set up toperform.

It is another object of the inventionto provide a novel and improvedindexing mechanism for imparting relative angular positioning movementsto the grinding wheel assembly and work support which will operateautomatically and with a high degree of precision to cause the work tobe located in diiferent angular positions with relation to the axis ofrotation of the grinding wheel assembly for the performance ofsuccessive grinding operations upon difierent faces of the work. Y

The invention is herein disclosed as embodied in a grinding machine ofthe general type adapted for cylindrical grindinghaving a worksupporting assembly including a longitudinally movable work table, aswivel support, and a headstock and footstock mounted thereon, agrinding wheel carriage movable toward and away from the work, and arotatable grinding wheel spindle having its axis parallel to the line ofmovement of the work table.

In accordance withthe invention, applicants provide a grinding wheelsleeve assembly comprising two oppositely faced disk grinding wheelsspaced to receive the work piece therebetween, and an automatic indexingmechanism for indexing the swivel support and work mounted thereonbetween alternate positions in which one and then the other face of thecutter is brought into the correct angular relation to the adjacentgrinding wheel for the performance of a relief grinding operationthereon.

The indexing mechanism herein disclosed as embodying certain features ofthe invention, comprises a pair of adjustable stops-for limitingmovement of the swivel support in each of its alternate indexedpositions, and actuating mechanism acting automatically when renderedoperative to shift the swivel support from one to the otherstop-engaging indexed position. In the preferred form of the invention,the actuating mechanism comprises a crank which is arranged to berotated through successive half revolutions,

and a yieldable connection between the crank and the swivel supportwhich is rendered operative by the rotation of .the crank to hold theswivel support under a'firm engaging pressure against each stop in turn.The automatic mechanism referred to, comprises an electric motor whichis connected to rotate the crank, a starting switch connection under thecontrol of the operator for starting the motor, and adog actuatedlimit'switch rendered operative at the end of each half revolution ofthe crank to disconnect the motor.

Further in accordance with the invention, a

I simple and efficient form of yielding connection is provided betweenthe crank and the swivel support which takes the form of a telescopicrod having two relatively movable telescoping links and aspring-actuated control device for maintaining the links yieldably inpredetermined relation to one another. The spring-actuated controldevice referred to, comprises a compression spring mounted in acylindrical chamber formed between the inner and outer link and arrangedto ment of parts hereinafter described and claimed,

which together with the advantages to be obtained thereby will bereadily understood by one skilled in the art from the followingdescription taken in connection with the accompanying drawings, in whichFig. 1 is a perspective view of the work supporting and grinding wheelassemblies of a grinding machine, illustrating particularly applicantstable indexing mechanism; Figs. 2 and 3 are detail views partl insection, showing the work in the two alternative positions with respectto the grinding wheel assembly for the performance of the two facerelieving operations upon a milling cutter; Fig. 4 isa detail view infront elevation Of the bracket on the swivel support connecting with thetelescoping rod of the indexing mechanism; Fig. 5 is a sectional viewlooking from the right, of the upper portion of the machine,illustrating particularly the indexing mechanism including thetelescopic connecting rod; Fig. 6 is an enlarged detail view partly insection, illustrating particularly a bracket mounted on the swivelsupport and formport about its swivel in each direction; Fig. 7 is adetail sectional. view taken on the line 1-1 of Fig. Fig. 8 is a detailbottom plan view taken on the line 8-8 of Fig. 5; Fig. 9 is a somewhatfragmentary plan view of the grinding machine shown in Fig. 1,illustrating particularly the grinding wheel assembly, the worksupporting assembly and the indexing mechanism; and Fig. 10 is anelementary electrical diagram of the machine.

Referring to the drawings, the cylindrical type grinding machineillustrated as embodying in a preferred form the several features of theinvention, comprises a base 28 having supported thereon a work table 22longitudinally movable on ways 24, and a swivel support 26 supported toturn on a pivot 28 on the table 22. Mounted on the swivel support 26 isa motor driven headstock unit 38 and a footstock unit 32, these partsbeing arranged to support between them a work piece in the form of amilling cutter 34 upon which a relief grinding operation is to beperformed.

The illustrated machine is provided also with a grinding wheel spindlecarriage 36 which is supported to move in a horizontal planetransversely toward and away from the work. The carriage 36 providessupport for a grinding wheel spindle indicated in dotted lines at 38 inFig. 5, a grinding wheel spindle driving motor 48, and a belt drivingconnection 42. The illustrated mach ne is provided with a .pair ofoppositely faced disk grinding wheels 44, 46 which are supported on asleeve mounting 48 secured to the spindle 38. Th grinding wheels 44, 46are spaced from one another a distance suflicient to permit the workpiece as, for example, the milling cutter 34, to be interposedtherebetween and to be manipulated for the performance of the reliefgrinding operations as hereinafter more fully set forth.

In accordance with the invention, applicants provide an indexingmechanism for swinging the swivel support between alternate positions inwhich the milling cutter 34 to be ground is brought to the desiredangular position with respect to the grinding wheel 44, and then withrespect to the grinding wheel 46 for the performance of relief grindingoperations upon the two faces of the milling cutter 34. The grindingwheels 44 and 46 are spaced from one another a suflicient distance topermit the swivel support 26 to be turned from one to the other positionwhile the cutter is disengaged from both grinding wheels. After theswivel support and work piece supported thereon have been indexed to thedesired position, the work table 22 is moved longitudinally to cause thework to be fed to depth with relation to the grinding wheel. The grindeing wheel spindle carriage and grinding wheel assembly thereon, aremaintained in their fully advanced position during the performance ofthe entire operation of grinding both faces of a work iece. p Themechanism for indexing the swivel support comprises a crank consistingof a disk 68, a crank pin 62 supported for adjustment radially thereon,and a telescopic connecting rod consisting generally of a link 64pivotally supported on the crank pin 62, and a link 66 pivotally sup-'ported on a pivot pin 68 on a bracket 18 secured to the right hand endof the swivel support 26. In order to provide for adjustment in thelength of the radius arm of the crank, the crank pin 62 is provided atits lower end with a squared head 88 which is fitted into an undercutslot 82 extending radially from the pivotal axis of the disk 68. Thecrank pin 62 is clamped rigidly in adjusted position by means of aclamping nut 84 which is screw-threaded to the upper end of the crankpin, and acts against a sleeve bearing'86 for the link 64 on the crankpin to force the same into clamping engagement with the upper surface ofthe disk 88.

The crank is arranged to be rotated through successive increments ofrotation, and acts through the yieldable connection provided by thetelescopic rod as hereinafter more fully to be described, to cause thesupport to be moved yieldably against a stop in each of its alternateindexed positions to provide an accurate and dependable positioning ofthe swivel support and work support thereon in the desired angularposition with relation to the axis of rotation of the grinding wheel forthe relief grinding of the opposed faces of a milling cutter supportedon the machine. As best shown in Figs. 5 and 6 of the drawings, thebracket 18 on the swivel support 26 is provided with a stop lug or plate88 which is arranged, for engagement with two adjustable stops 98 and 92which take the form of blocks slidably supported in an undercut slot 94extending across the upper face of the work table 22. The blocks areprovided respectively with stop screws 96 and 98 for engagement with thestop plate 88.

The construction and arrangement of the yieldable connection providedbetween the crank pin 62 and bracket 18 on the swivel support 26 will bereadily understood from an inspection of Fig. 5 of the drawings. Asshown in this figure, the telescopic link 66 is bored to receive one endof a rod I88 which is pinned thereto. The other end of the rod I88 isfitted to slide within a cylindrical bore I82 formed in a sleeve memberI94 screw-threaded into a bore in the end of the telescopic link 64. Thetelescopic links are maintained yieldably in predetermined relation toone another by means of a spring-actuated control device including acompression spring I86 coiled about the rod I88 between two collars I88and H8 loose on the rod I88. The collar II8 which takes the thrust ofthe spring I86 in one direction, is arranged to bear against a shoulderII2 formed by the end of the enlarged bore II 4 in the sleeve member I84within which the spring I86 is housed, and also against a shoulder II6formed by the end of the reduced stem portion of the shaft I88 on whichthe spring I86 is supported. The collar I88 which takes the thrust ofthe spring I86 in the opposite direction, is arranged to bear against asleeve element II8 screw-threaded to the shaft I88 and held in placethereon by a locking nut I28. The collar I88 bears also against aninwardly flanged portion I22 of a sleeve I 24 screw-threaded to theouter end of the sleeve member I84, so that the sleeve I24 and sleevemember I84 are connected to move as a unit with the telescopic link 64.A locking screw I26 serves to lock the sleeve I24 in adjusted positionon the sleeve member I84. With this construction and arrangement of thecooperating parts, it will readily be seen that the telescopic links 64,66 are normally maintained yieldably in an intermediate position inwhich the collar H8 is engaged with both of the abutments H2, H6, andthe collar I88 is engaged with the end of the sleeve element H8 and withthe inwardly flanged portion I22 of sleeve I24.

In operation, movement of the disk 80 and crank pin 82 rearwardly to theone of its alternate positions shown in Fig. 5, causes the connected endof the swivel support 28 to be moved rearwardiy. The lug 88 is thusbrought into engagernent with the stop pin 88, causing the link 84 to beextended slightly with respect to the link 88 as the crank pin 82 comesto rest in the limiting position shown. This extending movement of thetelescopic link 84 causes the inwardly flanged portion I22 of sleeve I24and collar I08 to be moved correspondingly to the right toward thecollar IIO, which is prevented from endwise movement by engagement withthe inner shoulder II8 on rod I forming a part of telescopic link 88.This relative movement of the collars I08 and H0 tends to compress thespring I08 so that the swivel support 28 and lug 88 are held yieldablybut firmly in engagement with the stop pin 88.

During the next succeeding 180 rotational movement of the disk 80 andcrank pin 82, the swivel support is moved to its alternate position inwhich the lug 88 is engaged against the stop screw 88 and the telescopiclinks 84 and 88 are relatively compressed against the pressure of springI08.to maintain the swivel support firmly in said alternate position.Compression of the spring I06 in this instance is caused by movement ofthe shouldered portion H2 of sleeve ele-,

ment I04 and collar IIO engaged thereby to the left toward collar I08which is prevented from endwise movement by engagement with the sleevenut II8 on the relatively stationary telescopic link 68 and rod I00.

It will be understood that adjustment of the effective pressure ofspring I08 is obtained by adjustment of the position of the sleeve nutH8 on shaft I00, and by a corresponding adjustment of the position ofsleeve I24 on sleeve member I04. Adjustment of the length of thetelescopic rod as a whole may be readily obtained without varying thepressure on the spring by rotating the sleeve member I04 to move thesame axially with respect to the telescopic link 84 having screwthreadedengagement therewith. During said latter adjustment, the sleeve I24 willbe turned as a unit with the sleeve member I04, these parts being heldagainst relative movement by means of the locking screw I26.

In the preferred construction illustrated in the drawings, the crankdisk 60 is arranged to be driven through successive half revolutions bymeans of an electric motor I30 and a reduction gear unit connecting themotor with the disk. As indicated in dotted lines in Fig. 5,

the drive is taken from the armature shaft I32v armature I32 and crankdisk 80 have turned' through 180. The electrical control devices forthis purpose comprise a manually operable start button I38, a manuallyoperable stop button I40, a limit switch I4'2, a limit switch actuatinglever I44, and trip dogs I48 and I48 which are supported in an annularslot I50 formed in the under face of the crank disk 60. The switch leverI44 is supported ona pivot I52 and is provided at its outer end with aroll I54 for engagement with the dogs I48 and I48. As best shown in theelementary wiring diagram Fig.' 10, the motor I30 there referred to asthe attachment motor, is arranged to be energized by means of a solenoidactuated switch AR. The pressing of the start button I38 will close thestarting contacts ll-18 to energize the solenoid AR for starting themotor I30. AR contact 19-18 closes forming a holding circuit to maintainthe solenoid AR energized. At the end of a half revolution of the crankdisk 80 and crank pin 82, one of the dogs I48, I48 will be brought intoengagement with the roll I54 to rock the switch actuating lever I44,thus opening contact 1119 to de-energize the solenoid AR and stop theat- 20 tachment motor I80. At the same time contact AR 1818 opens, sothat the motor remains stopped.

It will be understood that the invention is not limited to the specificembodiment shown, and that various deviations may be made therefromwithout departing from the spirit and scope of the appended claims.

What is claimed is: 1. -In a cylindrical type grinding machine hav ing agrinding wheel assembly arranged for the grinding of different faces ofthe work, a rotary grinding wheel spindle, a rotary work support, and aswivel support movable between alternate indexed positions to alter theangular relation of the grinding wheel spindle and work holder axes forthe performance of successive face grinding operations on each of saiddifierent faces, and an indexing mechanism comprising power means,amanually operable starting control, connections rendered operative bythe actuation of said control to render said power means operative toshift said swivel support from one to the other of said alternatepositions, and a limit control responsive to the movement of the supportto either of said alternate positions to render said power meansinoperative.

2. In a cylindrical type grinding machine having a grinding wheelassembly arranged for the grinding of different faces of the work, arotary grinding wheel spindle, a rotary work support, and a swivelsupport movable between alternate indexed positions to alter the angularrelation of the grinding wheel spindle and the work holder axes for theperformance of successive face grinding operations on each of saiddifferent faces, and an indexing mechanism comprising stops forpositively limiting swinging movement of said swivel support in each ofsaid positions, power actuating means including a yieldable connectionfor engaging and supporting the -swivel support against the associatedstop in each indexed position, and means under the control of theoperator for rendering said power'actuating means operative to index thesupport.

3. In a cylindrical type grinding machine having a grinding wheelassembly arranged for the grinding of different faces of the work, arotary grinding wheel spindle, a rotary work support, and a swivelsupport movable between alternate indexed positions to alter the angularrelation of the grinding wheel spindle and the work holder axes for theperformance of successive face grinding operations on each of saiddifferent faces, and an indexing mechanism comprising stops forpositively limiting angular movement of the swivel .tor for rotatingsaid crank through successive half revolutions.

4. In a cylindrical type grinding machine having a grinding wheelassembly arranged for the grinding of different faces of the work, arotary grinding wheel spindle, a rotary work support,

and a swivel support movable between alternate indexed positions toalter the angular relation of the grinding wheel spindle and the workholder axes for the performance of successive face grinding operationson each of said different faces, and an indexing mechanism comprisingstops for positively limiting angular movement of the swivel support ineach of said positions, a crank and a yieldable connection therefromwith the swivel support constructed and arranged for each successivehalf revolution of the crank to shift and to yieldablyengage the swivelsupport against the associated stop in each alternate indexed position,an electric motor and connections therefrom for rotating the crank, astarting switch for the motor, a limit switch, and dogs associated withthe crank for actuating the limit switch to stop the motor at thecompletion of each successive half revolution of the crank.

5..In a cylindrical type grinding machine having a grinding wheelassembly arranged for the grinding of different faces of the work, arotary grinding wheel spindle, a rotary work support, and a swivelsupport movable between alternate indexed positions to alter the angularrelation of the grinding wheel spindle and the work holder axes for theperformance of successive face grinding operations on each of saiddifferent faces, and an indexing mechanism comprising stops forpositively limiting angular movement of theswivel support in each ofsaid positions, a crank, a telescopic rod connecting the crank with theswivel support, said telescopic rod comprising telescoping links, andmeans connecting said links tending to maintain said links yieldablyagainst relative movement from a position of predetermined length ofsaid rod either into or away from each other, said crank and telescopicrod being constructed and arranged for each successive half revolutionof the crank to shift and to yieldably engage the swivel support againstthe associated stop in each alternate indexed position, and means underthe control of the operator for rotating said crank through successivehalf revolutions.

6. In a cylindrical type grinding machine having a grinding wheelassembly arranged for the grinding of different faces of the work, arotary grinding wheel spindle, a rotary work support, and a swivelsupport movable between alternate indexed positions to alter the angularrelation of the grinding wheel spindle and the work holder axes for theperformance of successive face grinding operations on each of saiddifferent faces, and an indexing mechanism comprising stops forpositively limiting angular movement of the swivel support in each ofsaid positions, a crank, a telescopic rod providing a yieldableconnection between the crank and the swivel support, said telescopic rodcomprising telescoping links having formed in the telescoping portionsthereof superimposed shouldered cylindrical recesses of equal length, acoiled compression spring housed within the space formed by saidrecesses and arranged at each end to act against the recessed shouldersof both links, said crank and telescopic rod I being constructed andarranged for each successive half revolution of. the crank to shift andto yieldably engage the swivel support against the associated stop ineach alternate indexed position, and means under the control of theoperator for rotating said crank through silocessive half revolutions.

'7. In a cylindricaltype grinding machine having a grinding wheelassembly arranged for the grinding of different faces of the work, arotary grinding wheel spindle, a rotary work support, and a swivelsupport movable between alternate indexed positions to alter the angularrelation of the grinding wheel spindle and the work holder axes for theperformance of successive face grinding operations on each of saiddifferent faces, and an indexing mechanism comprising stops forpositively limiting angular movement of .the swivel support in each ofsaid positions, a crank, a telescopic rod providing a yieldableconnection between the crank and the swivel support, said telescopic rodcomprising an inner link having a shouldered portion and an axiallyadjustable collar spaced therefrom to form a shouldered recess ofadjustable length, an outer link having a sleeve member secured to andaxially adjustable with relation to the outer link for receiving theinner link, said sleeve member having formed therein a shoulderedportion overlying the shouldered portion formed on the inner link, and asleeve axially adjustable on the sleeve member and having an inwardlyflanged end portion overlying said collar to provide a shouldered recessof adjustable length on the outer link, a compression spring coiledabout the inner link in the space provided by said recesses and arrangedfor engagement at each end against the shoulders associated with boththe inner and outer links, and means under the control of the operatorfor rotating said crank through successive half revolutions.

8. In a cylindrical type grinding machine, the combination of a base, alongitudinally movable work support, a work table, a swivel supportmounted thereon, and a rotary work holder on the swivel support, agrinding wheel support and a grinding wheel spindle having supportedthere-' on a grinding wheel assembly arranged for grinding differentfaces of the work, and means for indexing the swivel support betweenalternate positions for the performance of the grinding operation oneach of said different faces comprising stops for positively limitingrotational movement of the swivel support in each of said alternatepositions, a crank, a telescopic rod connecting the crank and the swivelsupport, said crank and connecting rod being constructed and arrangedfor movement in excess of that required to move the swivel supportbetween said positions, spring means tending to maintain the connectingrod at a predetermined length, a'motor and reduction gearing therefromfor rotating the crank, a starting switch for the motor, and controlmeans for disconnecting the motor following each succeeding halfrevolution of the crank to move the swivel support from one to the otherof said positions.

9. In a cylindrical type grinding machine having a grinding wheelassembly arranged, for the grinding of different faces of the work,arotary grinding wheel spindle, arotary work support, and a swivelsupport movable between altemateindexed positions to alter the angularrelation of the grinding wheel spindle and work holder axes for theperformance of successive face grinding operations on each of saiddifferent faces, and an indexing mechanism comprising an electric motorand braking means associated therewith, and connections from the motorincluding a crank for oscillating the support between said alternateindexed positions, a starting switch for the motor, a limit switchrendered operative by movement of the support to either indexedposition, and connections rendered operative by said switch todisconnect the motor and set the brake.

ADRIEN E. MANDEVILLE. LESTER J. LALIME.

